S-99291A450 5/16"-24 Locknuts

Key Features & Benefits at a Glance

• Superior vibration resistance through distorted top lock thread design, preventing loosening in high-stress environments
• Enhanced corrosion protection with black-oxide steel finish, extending service life in demanding industrial conditions
• Reliable strength performance meeting ASTM Grade C specifications, ensuring consistent load-bearing capacity
• Precise thread engagement with Class 2B thread fit, providing smooth installation and secure fastening
• Standard external hex drive design for compatibility with common tools and efficient installation
• Environmental compliance with RoHS 3 and REACH standards, suitable for regulated industrial applications
• Fine UNF thread profile offering better tension control and superior holding power compared to coarse threads

Professional Applications & Engineering Value

This 5/16"-24 UNF locknut delivers critical vibration resistance in demanding industrial applications where secure fastening is paramount. The distorted thread locking mechanism at the top section creates intentional interference, generating constant friction that counters rotational forces from machinery vibration and dynamic loads. Manufactured from black-oxide steel, this heavy-duty fastener provides superior corrosion resistance while maintaining the structural integrity required for ASTM Grade C applications. The fine UNF thread profile ensures precise tension control and better stress distribution, making it ideal for automotive assemblies, industrial machinery, and equipment subjected to continuous operational stresses. The external hex drive design allows for quick installation with standard tools, reducing assembly time while maintaining reliable performance in high-vibration environments.

Specification Summary & Compliance

This heavy-duty locknut features precise Class 2B thread fit tolerances with 5/16"-24 UNF fine threads in right-hand direction. The fastener meets ASTM Grade C strength requirements and incorporates top lock distorted thread technology for secure locking performance. Manufacturing complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental standards, ensuring regulatory compliance for industrial use. Physical dimensions include 1/2" width across flats and 17/64" height for standard installation requirements.